[...]The key word in the embassy report apparently is the term “relinquishment.” That means, a knowledgeable source told us, that she did not “formally renounce her U.S. citizenship under 349(a)(5) Immigration and Nationality Act, but took Swiss citizenship with the intent to lose her U.S. citizenship.” As opposed to formal renunciation — a much more complex process, we were told — there are no “tax or other penalties for loss of citizenship in this fashion.”